Stable pesticide dispersions

ABSTRACT

Stable dispersions of certain pesticides in agricultural oil are provided. In particular, the dispersions include a particulate pesticide, agricultural oil, and an agricultural oil-soluble polymer, the polymer in some instances containing a copolymerized polar monomer. Also provided is a method for forming the stable dispersion.

The present invention relates to a stable dispersion of a pesticide inan agricultural oil and a method for forming the dispersion. Inparticular the invention relates to a stable dispersion of a pesticidein an agricultural oil including: a pesticide having a particle sizefrom 0.5-10 microns and selected from the group consisting ofchlorinated nitrile, triazole, aralkyl triazole, triazole anilide,benzamide, alkyl benzamide, diphenyl ether, pyridine carboxylic acid,chloroaniline, organophosphate, phosphonic glycine salt, and mixturesthereof; an agricultural oil; and an agricultural oil-soluble polymer,the polymer having a weight average molecular weight from 3,000 to120,000 and including 2.5-35% by weight of a copolymerized polarmonomer. And the invention is related to a stable dispersion of apesticide in an agricultural oil comprising: ethylene bisdithiocarbamatehaving a particle size from 2-10 microns; an agricultural oil; and anagricultural oil-soluble polymer, said polymer having a weight averagemolecular weight from 3,000 to 90,000 and including 0-35% by weight of acopolymerized polar monomer. The invention is also related to a methodfor forming the stable dispersion.

U.S. Pat. No. 3,773,926 discloses a method of and composition for thetreatment of plants, the compositions containing certain pesticidesdispersed in a conventional agricultural oil employing anN-vinyl-2-pyrrolidinone (4-15%)/alkyl methacrylate (85-96%) copolymerdispersant. The dispersant polymer is disclosed to have a averagemolecular weight of from about 300,000 to about 1,000,000.

U.S. Pat. No. 3,131,119 discloses compositions containing salts ofdithiocarbamic acids such as ethylenebisdithocarbamic acid anddimethyldithiocarbamic acid dispersed in oil using an organicsolvent-soluble polymer which possesses a balance of hydrophilic andlipophilic groups. The lipophilic groups are supplied by hydrocarbongroups containing from 8-24 carbon atoms. The hydrophilic groups aresupplied by multiple ether groups, carbonyl groups, carboxylic acidgroups, carboxylic ester groups, amide groups, and amino groups. Theorganic solvent-soluble polymer is disclosed to have a molecular weightof about 100,000 to about 2,000,000.

There remains the need for stable dispersion of a variety of pesticides.We have now surprisingly found that a variety of stable dispersions canbe made using agricultural oil-soluble polymers having a lower molecularweight than previously disclosed. These compositions facilitate makingand storing of the dispersions, also considered as concentrates, even inhot climates, for their effective use in agronomic applications.Accordingly, the present invention provides a stable dispersion ofcertain pesticides in an agricultural oil and a method for forming thestable dispersion.

According to a first aspect of the present invention there is provided astable dispersion of a pesticide in an agricultural oil comprising: apesticide having a particle size from 0.5-10 microns and selected fromthe group consisting of chlorinated nitrile, triazole, aralkyl triazole,triazole anilide, benzamide, alkyl benzamide, diphenyl ether, pyridinecarboxylic acid, chloroaniline, organophosphate, phosphonic glycinesalt, and mixtures thereof; an agricultural oil, and an agriculturaloil-soluble polymer, the polymer having a weight average molecularweight from 3,000 to 120,000 and including 2.5-35% by weight of acopolymerized polar monomer

According to a second aspect of the present invention there is providedstable dispersion of a pesticide in an agricultural oil comprising:ethylene bisdithiocarbamate having a particle size from 2-10 microns; anagricultural oil; and an agricultural oil-soluble polymer, the polymerhaving a weight average molecular weight from 3,000 to 90,000 andincluding 0-35% by weight of a copolymerized polar monomer.

According to a third aspect of the present invention there is provided amethod for forming a stable dispersion of a pesticide in an agriculturaloil comprising admixing a pesticide selected from the group consistingof chlorinated nitrile, triazole, aralkyl triazole, triazole anilide,benzamide, alkyl benzamide, diphenyl ether, pyridine carboxylic acid,chloroaniline, organophosphate, phosphonic glycine salt; an agriculturaloil; and an agricultural oil-soluble polymer, the polymer having aweight average molecular weight from 3,000 to 120,000 and including2.5-35% by weight of a copolymerized polar monomer and mixing orshearing the admixture until the pesticide has a particle size from 0.5to 10 microns.

According to a fourth aspect of the present invention there is provideda method for forming a stable dispersion of a pesticide in anagricultural oil comprising admixing ethylene bisdithiocarbamate; anagricultural oil; and an agricultural oil-soluble polymer, said polymerhaving a weight average molecular weight from 3,000 to 90,000 andincluding 0-35% by weight of a copolymerized polar monomer and mixing orshearing the admixture until the ethylene bisdithiocarbamate has aparticle size from 2 to 10 microns.

By “stable dispersion of a pestcide in an agricultural oil” herein ismeant a dispersion which did not gel during the dispersion process,i.e., a dispersion which did not gel, for example, in the homogenizer,bead mill, or ball mill used to mix and shear the admixture of thepesticide, the polymer, and the agricultural oil. The stable dispersionis stable relative to a dispersion of the same pesticide prepared inlike manner in the absence of the polymer. Prefered are dispersionswhich, in addition meet the inital properties below. More prefered aredispersions which further meet the following properties after 1-2 weeksholding at 54 C. Typical desired values of the measured properties aregiven.

Initial Properties:

appearance=no gelling

viscosity=less than 2000 cps,

most preferably less than 1000 cps

After 1-2 weeks at 54° C.:

appearance=no gelling

viscosity=less than 2000 cps,

most preferably less than 1000 cps

% separation=top clear liquid; separation less than 10%.

sedimentation=sticky sediment on the bottom of jar; none.

By “particle size” herein is meant the volume average particle diameteras measured, for example by a laser particle size instrument such as theCoulter LS-130 particle sizer.

Pesticides herein include particulate agronomically effectivefungicides, herbicides, and insecticides such as chlorinated nitrile,triazole, aralkyl triazole, triazole anilide, benzamide, alkylbenzamide, diphenyl ether, pyridine carboxylic acid, chloroaniline,organophosphate, phosphonic glycine salt, and mixtures thereof Alsoincluded are mixtures of the pesticides with other organic or inorganicagronomically active ingredients, for example, Dithane+Indar,Dithane+chlorothalonil, Dithane+cymoxanil, and Dithane+Copper Hydroxide.Examples of typical pesticides and their physical characteristics arepresented in Table 1.

TABLE 1 Typical Pesticides used in this invention Melting Pt Sol. inTrade Name Action Common Name Family Molecular Formula ° C. H2O Bravofungicide Chlorothalonil chlorinated nitrile C8CL4N2 250-251 0.6-1.2 ppmDithane fungicide Mancozeb ethylene C4H6MNN2S4x Zny 192-204 6-20 ppmbisthiocarbmate Systhane fungicide Myclobutanil triazole C15H17ClN463-68 142 ppm Indar fungicide Fenbunconazole aralkyl triazole C19H17ClN4124-126 0.2 ppm Pulsar fungicide Thifluzamide C13H6Br2F6N2OS 178 1.6 ppmRH-7281 fungicide n/a alkyl benzamide C14H16O2NCl3 167 >1 ppm Galleryherbicide Isoxaben amide C18H24N2O4 176-179 1-2 ppm Kerb herbicidePronamide amide C12H11CL2NO 155-156 15 ppm Visor herbicide Thiazopyrpyridine C16H17O2N2SF5 79-81 2.5 ppm carboxylic acid Goal herbicideoxyfluorfen diphenyl ether C15H11ClF3NO4 85-90 0.1 ppm Stam herbicidepropanil chloroaniline C9H9Cl2NO 91 130 ppm Roundup herbicide glyphosatephosphonic C6H17N2O5PS >200 40-50% isopropyl ammonium salt glycine saltImidan insecticide Phosmet organophosphate C11H12NO4PS2 72.0-72.7 25 ppm

Notes: Dithane, Systhane, Indar, Pulsar, Kerb, Visor, Goal, and Stam aretrademarks of Rohm and Haas Company. Bravo is a trademark of ISKBiosciences, Gallery is a trademark of Dow Elanco. Imidan is a trademarkof Gowan Co. Roundup is a trademark of Monsanto Co. RH-7281 is a productof Rohm and Haas Company.

Typically the pesticides used in the stable dispersion and method forforming a stable dispersion of this invention were crystalline and hadmelting points greater than 50° C., molecular weights greater than 200,low solubility in paraffinic solvents, typically less than 1%, andcontained polar functional groups such as, for example, ester, carbonyl,hydroxy, and cyano.

The agricultural oils used in the stable dispersions and method forforming a stable dispersion of this invention are oils suitable foragronomic application, typically of high purity, and generally composedof a single aliphatic chemical structure. They may be branched or linearin nature with typical carbon chain lengths of C₂₀ to C₂₆. They arecharacterized by low odor, low solvency for organic and organo-metalliccompounds, low phytotoxicity to biological species, and low volatility.Commercial examples agricultural oil are: Orchex 796, Orchex 692,Sunspray 7N, Sunspray 11N, Oleo Branco, Isopar M, Isopar V, 100 Neutral,and Exxsol D-130. Other oils such as mineral oil; crop oil such as, forexample, vegetable oil, peanut oil, and cottonseed oil; or synthetic maybe acceptable

Typical physical characteristics of agricultural oils are:

Specific Gravity at 60/60° F. 0.750 to 0.900 Flash Point >120° F.Viscosity, SSU at 100° F. 50 to 150 Unsulfonated residue >90%Distillation range 350° F. to 450° F.

The agricultural oil-soluble polymers used in the stable dispersion andmethod for forming a stable dispersion of this invention typically areaddition polymers formed from ethylenically unsaturated monomers.Prefered are copolymers of one or more monomers, the homopolymers ofwhich are soluble in agricultural oils, and one or more polar monomers.More prefered are copolymers of one or more alkyl (meth)acrylates andone or more polar monomers.

Examples of the alkyl (meth)acrylates [alkyl(meth)acrylates is usedherein to mean alkyl methacrylate or alkyl acrylate where the alkylgroup contains from 1 to 15 carbon atoms are methyl methacrylate (MMA),methyl acrylate, ethyl acrylate, propyl methacrylate, butyl methacrylate(BMA) and acrylate (BA), isobutyl methacrylate (IBMA), hexyl andcyclohexyl methacrylate, cyclohexyl acrylate 2-ethylhexyl acrylate(EHA), 2-ethylhexyl methacrylate, octyl methacrylate, decylmethacrylate, isodecyl methacrylate (IDMA, based on branched (C₁₀)alkylisomer mixture), undecyl methacrylate, dodecyl methacrylate (also knownas lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate(also known as myristyl methacrylate), pentadecyl methacrylate andcombinations thereof Also useful are: dodecyl-pentadecyl methacrylate(DPMA), a mixture of linear and branched isomers of dodecyl, tridecyl,tetradecyl and pentadecyl methacrylates; and lauryl-myristylmethacrylate (LMA), a mixture of dodecyl and tetradecyl methacrylates.Examples of the alkyl (methacrylate) where the alkyl group contains from16 to 24 carbon atoms are hexadecyl methacrylate, heptadecylmethacrylate, octadecyl methacrylate, nonadecyl methacrylate, eicosylmethacrylate, behenyl methacrylate(BehMA), and combinations thereof.Also useful are: cetyl-eicosyl methacrylate (CEMA), a mixture ofhexadecyl, octadecyl and eicosyl methacrylate; and cetyl-stearylmethacrylate (SMA), a mixture of hexadecyl and octadecyl methacrylate.

The alkyl methacrylate and alkyl acrylate monomers described above aregenerally prepared by standard esterification procedures using technicalgrades of long chain aliphatic alcohols, and these commerciallyavailable alcohols are mixtures of alcohols of varying chain lengthscontaining between 10 and 15 or 16 and 20 carbon atoms in the alkylgroup. Consequently, for the purposes of this invention, alkylmethacrylate is intended to include not only the individual alkylmethacrylate product named, but also to include mixtures of the alkylmethacrylates with a predominant amount of the particular alkylmethacrylate named. The use of these commercially available alcohols toprepare acrylate and methacrylate esters results in the LMA, DPMA, SMAand CEMA monomer mixtures described above.

The polar monomers may contain, for example hydroxy groups orNitrogen-containing groups. The polar monomers preferably containhydroxyl, carboxylic acid, basic nitrogen, or heterocyclicfunctionality. Examples of polar monomers arehydroxyalkyl(meth)acrylates such as hydroxypropyl methacrylate(HPMA),dialkylamino(C₁-C₈)alkyl (meth)acrylates such as dimethylaminoethylmethacrylate(DMAEMA) and dialkylamino(C₁-C₈)alkyl (meth)acrylamides suchas dimethylaminopropyl methacrylamide(DMAPMAm), vinylpyridine,2-methyl-5-vinylpyridine, 2-ethyl-5-vinylpyridine,3-methyl-5-vinylpyridine, 2,3-dimethyl-5-vinylpyridine,2-methyl-3-ethyl-5-vinylpyridine, methyl-substituted quinolines andisoquinolines, 1-vinylimidazole, 2-methyl-1-vinylimidazole(MVI),N-vinylcapro-lactam, N-vinylbutyrolactam and N-vinylpyrrolidone(NVP).

To achieve oil solubility in a typical agricultural oil, the alkyl sidechains of the acrylate/methacrylate monomers should average at leastabout C₇-C₉. However, typically as the amount of the polar monomer inthe polymer increases, the average chain length of the alkyl side chainsin the (meth)acrylate comonomers must be increased, in order to maintainoil solubility. Therefore, a polymer that contains greater than 10% byweight of copolymerized DMAPMAm (basic nitrogen) or copolymerized HPMA(free hydroxyl) typically requires a greater amount of alkyl side chainscontaining C₁₆-C₁₈ alkyl rather than C₇-C₉ alkyl. Prefered arecopolymers of C₁₂-C₂₀ methacrylates with 10-15% by weight of DMAPMAm.More prefered are coplymers of stearyl methacrylate(SMA) with 10-20% byweight of DMAPMAm.

The weight average molecular weight of the polymer, typically from 3,000to 120,000 or from 3,000 to 90,000, depending on the pesticide to bedispersed, may also have an effect on the viscosity of the formulation,with higher molecular weight leading to higher solution viscosity.Higher solution viscosity may decrease particle mobility and thus delayseparation and settling. However, higher solution viscosity may hinderthe flowability, transfer, and facile dilution of the pesticidedispersion Prefered are weight average molecular weights of 15,000 to90,000; more prefered are weight average molecular weights of 20,000 to75,000.

The polymers are typically made by addition polymerization inagricultural oil, preferably by gradual addition free-radicalpolymerization of the monomers. The polymers are typically prepared bymixing the monomers in the presence of a polymerization initiator,agricultural oil and, optionally, a chain transfer agent. The reactionmay be run under agitation in an inert atmosphere at a temperature offrom about 60 to 140° C. and more preferably from 115 to 125° C. Thereactions were typically run for about 4 to 10 hours or until thedesired degree of polymerization hadbeen reached. As is recognized bythose skilled in the art, the time and temperature of the reaction aredependent on the choice of initiator and can be varied accordingly.Polymers may be prepared by techniques known in the art to form graftpolymers, block copolymers, star copolymers, or variable compositioncopolymers as well as random copolymers.

Initiators useful for this polymerization are any of the well knownfree-radical-producing compounds such as peroxy, hydroperoxy and azoinitiators including acetyl peroxide, benzoyl peroxide, lauroylperoxide, t-butyl peroxyiso-butyrate, caproyl peroxide, cumenehydroperoxide, 1,1-di(t-butylperoxy)-3,3,5-tri-methylcyclohexane,azobisisobutyronitrile, 2,2′azobis(2-methylbutane nitrile), and t-butylperoctoate. The initiator concentration is normally between 0.025 and 1%by weight based on the total weight of the monomers and more preferablyfrom 0.05 to 0.25%. Chain transfer agents may also be added to thepolymerization reaction to control the molecular weight of the polymer.The prefered chain transfer agents are alkyl mercaptans such as lauryl(dodecyl) mercaptan, and the concentration of chain transfer agent usedis from about 0.1 to about 10% by weight.

The dispersion of a pesticide in agricultural oil was typically effectedwith pesticides which were either technical grade particulatepesticides(“technicals”) or formulated particulate pesticidecompositions such as, for example, wettable powders and dispersiblegranules.

The technical grade particulate pesticides ranged in active ingredientcontent from 80 to 98% by weight and were solid at room temperature. Thewettable powders and dispersible granules ranged in active ingredientcontent from 45% by weight to 75% by weight and had typical compositionsas follows: 45 to 75% by weight pesticide; 20 to 50% by weight carrier;2 to 10% by weight dispersant; and 2 to 10% by weight surfactant. Thewettable powders and dispersible granules typically had been milled toan average particle size in the range of 2 to 10 microns.

The dispersions of this invention are typically applied in the field asdilutions into oil or oil/water/surfactant carriers. The spray tankmixtures may contain other formulated agronomic compositions such as,for example, surfactant adjuvants, emulsifiable concentrates, andwettable powders. Application may be made by ground or aerial sprayequipment.

EXAMPLE 1

Preparation of agricultural oil-soluble polymer

Preparation of polymer 3. A 5 gallon reactor was fitted with athermocouple, a temperature controller, a purge gas inlet, awater-cooled reflux condenser with purge gas outlet, a stirrer, and anaddition tank. To the addition tank was charged 4911.59 grams of amonomer mixture of 4137.07 pbw stearyl methacrylate (96.5% purity),704.52 pbw dimethylaminopropyl methacrylamide (100% purity), 40.00 pbwof a 50% solution of t-butyl peroctoate in mineral spirits (LupersolPMS), 30.00 pbw dodecyl mercaptan. Sixty percent (2946.95 grams) of themonomer mixture in the addition tank and 736.74 grams of Orchex 796 oilwere charged to the reactor which was then flushed with nitrogen for 30minutes before applying heat to bring the contents of the reactor to120° C. When the contents of the reactor reached 120° C., the balance ofthe monomer mixture in the addition tank was uniformly charged to thereactor over 90 minutes. At the end of the monomer mixture addition, thetemperature in the reactor was lowered to 100° C. and 1124.21 grams of afeed consisting of 314.21 pbw stearyl methacrylate, 60.00 pbw of a 50%solution of t-butyl peroctoate in mineral spirits (Lupersol PMS), and750.00 pbw Orchex 796 oil was added uniformly over 120 minutes. Then thecontents of the reactor were held 30 minutes at 100° C. At the end ofthe hold, the reaction temperature was raised to 120° C. and 260.00grams of a 10.00 pbw of a 50% solution of t-butyl peroctoate in mineralspirits (Lupersol PMS) and 250.00 pbw Orchex 796 oil was added to thereactor. The reaction was held at 120° C. for 30 minutes. At the end ofthe 30 minute hold, 6000.00 grams of Orchex 796 oil was added to thebatch. The batch was then held at ˜120° C. for an additional 30 minuteto create a homogeneous solution. The product so formed exhibited apolymer solids content of 32.65 wt %, a viscosity of 38 centistokes at100° C. (210° F.). Monomer conversion to polymer was calculated to be98%.

EXAMPLE 2

Preparation of agricultural oil-soluble polymer with grafted polarmonomer.

Preparation of Polymer No. 38 (Table 2). A 1 liter reactor was fittedwith a thermocouple, a temperature controller, a purge gas inlet, awater-cooled reflux condenser with purge gas outlet, a stirrer, and anaddition funnel. To the addition funnel was charged 259.39 grams of amonomer mixture of 230.77 parts by weight (pbw) stearyl methacrylate(97.5% purity), 12.50 pbw dimethylaminopropyl methacrylamide (100%purity), 1.50 pbw of a 50% solution of t-butyl peroctoate in mineralspirits (Lupersol PMS), 2.13 pbw dodecyl mercaptan. Thirty percent(77.82 grams) of the monomer mixture in the addition funnel was chargedto the reactor which was then flushed with nitrogen for 30 minutesbefore applying heat to bring the contents of the reactor to 115° C.When the contents of the reactor reached 115° C., the balance of themonomer mixture in the addition funnel was uniformly charged to thereactor over 60 minutes. At the end of the monomer mixture addition,38.50 grams of a chaser feed consisting of 1.00 pbw of a 50% solution oft-butyl peroctoate in mineral spirits (Lupersol PMS), and 37.50 pbwOrchex 796 oil was added uniformly over 90 minutes. Thirty minutes intothe chaser feed, 12.50 grams of dimethylaminopropyl methacrylamide (100%purity) was charged to the reactor over 15 minutes as a separate feed.At the end of the chaser feed the contents of the reactor were held 60minutes at 115° C. At the end of the 60 minute hold, 522.94 grams ofOrchex 796 oil was added to the batch. The batch was then held at ˜115°C. for an additional 30 minute to create a homogeneous solution. Theproduct so formed exhibited a polymer solids content of 28.53 wt %, aviscosity of 22 cSt at 100° C. (210° F.) Monomer conversion to polymerwas calculated to be about 95%.

EXAMPLE 3

Preparation of additional agricultural oil-soluble polymers

Additional polymers were prepared according to the method of Example 1.Compositions and physical characteristics are presented in Table 2below.

TABLE 2 Polymer Compositions and physical characteristics Polymer No.Composition Monomer Weight % Mol. wt. Solids 1 BehA/DMAPMAm 90/10 29,40027.6 2 BehMA/DMAPMAm 90/10 54,500 30.8 3 SMA/DMAPMAm 85/15 32,800 32.7 4CEMA/IDMA/MMA 28/62/10 49,600 39.0 5 CEMA/IDMA/MMA/DMAPMAm25.2/55.8/9/10 31,400 39.6 6 CEMA/IDMA/MMA/DMAPMAm 26.5/58.9/9.5/557,900 38.2 7 CEMA/IDMA/MMA/NVP 30/56/10/4 420,000  39.1 8CEMA/LMA/DMAPMAm 4.5/91.5/4 45,900 9 CEMA/LMA/DMAPMAm 15/65/20 35,000 10CEMA/LMA/IBMA/NVP 32.7/43.8/13.7/9.8 256,000  38.6 11 IDMA/DMAPMAm 85/1519,700 29.6 12 IDMA/MMA 80/20 49,400 29.6 13 LMA 100 55,200 34.0 14LMA/DMAPMAm 90/10 32,700 50.0 15 LMA/DMAPMAm 60/40 18,700 28.1 16LMA/HPMA 90/10 64,800 31.5 17 LMA/IDMA 50/50 49,100 26.8 18 LMA/MMA86.2/13.2 47,900 74.0 19 LMA/MMA 90/10 47,900 74.0 20 LMA/NVP 90/1068,800 30.2 21 LMA/NVP 80/20 68,000 34.8 22 SMA/DMAEMA 95/5 49,200 29.323 SMA/DMAEMA 90/10 50,600 29.3 24 SMA/DMAEMA 80/20 52,300 29.1 25SMA/DMAPMAm 95/5 44,400 29.4 26 SMA/DMAPMAm 95/5 77,700 28.7 27SMA/DMAPMAm 90/10 35,300 22.7 28 SMA/DMAPMAm 90/10 88,200 28.0 29SMA/DMAPMAm 90/10 94,000 29.3 30 SMA/DMAPMAm 80/20 20,600 29.6 31SMA/DMAPMAm 80/20 25,600 27.9 32 SMA/DMAPMAm 70/30 20,000 28.9 33SMA/DMAPMAm 60/40 17,600 30.2 34 SMA/DMAPMAm 85/15 18,600 28.8 35SMA/DMAPMAm 85/15 20,800 30.3 36 SMA/DMAPMAm 85/15 22,000 30.0 37SMA/DMAPMAm 85/15 27,600 27.9 38 SMA/DMAPMAm (5% grafted) 90/5/5 50,60028.5 39 SMA/DMAPMAm (toluene) 90/10 27,200 51.4 40 SMA/IDMA 50/50 56,60030.8 41 SMA/IDMA/MMA/HPMA 30.3/60.7/4/5 302,000  47.0 42SMA/IDMA/MMA/NVP 30/56/10/4 237,000  47.5 43 SMA/MVI 90/10 73,900 29.444 BehMA/LMA/DMAPMAm 48/37/15 28,500 30.0 45 SMA/DMAPMAm 85/15 200,000 30.0 46 SMA/DMAPMAm 85/15 180,000  30.0 47 SMA/DMAPMAm 85/15 94,000 30.048 SMA/DMAPMAm 85/15 85,000 30.0 49 SMA/DMAPMAm 85/15 43,000 30.0 50SMA/LMA/NVP 31.5/58.5/10 46,700 48.7 51 SMA/DMAPMAm 85/15 25,900 52SMA/LMA/DMAPMAm 31.5/58.5/10 28,600 53 SMA/DMAPMAm 85/15 25,900 48.9

EXAMPLE 3

Preparation and exaluation of dispersions of pesticides.

Compositions tested were typically:

Pesticide solids 50 parts Polymer solids* 0 to 5.0 parts Orchex 796 oil42 to 50 parts *provided in oil as 27% to 74% solids

All samples in Table 3 were prepared either at 0%, denoted as “none” forPolymer No. or at 5% by weight of polymer solids, except for experimentswith Polymer No. 18 which was incorporated at 2% polymer solids byweight. Polymer was weighed into a tared stainless steel beaker and thenOrchex 796 oil was added. The mixture was hand mixed with a spatula.Pesticide was weighed onto weighing paper and slowly added to thepolymer/oil mixture with stirring. The mixture was hand mixed thoroughlywith a spatula.

Samples too viscous to homogenize directly and dry flowable compositionswere pre-dispersed before homogenization. The sample was run until itwas a well mixed and flowable mixture.

All samples were homogenized using a a Silverson Model L4R homogenizer.The power dial was slowly increased to ⅔ power. Samples made fromtechnicals and wettable powders were homogenized for 10 minutes. Dryflowables were homogenized until the granules appeared uniformlydispersed. Samples were also mixed during homogenization by gentlyswirling the sample container. Samples were evaluated as free flowingliquid (reported as “ok”) or gelling (reported as “gel”).

Bead (Eiger) milling was carried out for for those compositions startingwith course particle size pesticides. The 50 ml Eiger mill (Model M50from Eiger Machinery, Inc.) was loaded with 45 ml of 1 mm glass beadsinto the bead chamber. Cooling water was turned on. 2.54 cm (one inch)of sample was poured into the sample funnel. The mill was run with thesample mixture for one minute at 3500 rpm. The sample was dischargedinto a waste container and blown-out to push additional sample from themill. The remaining sample was added to the sample funnel. The samplewas milled for ten to thirty minutes at 3500 rpm. This treatment wasbelieved to be sufficient to provide a dispersion of pesticide having aparticle size of 0.5-10 microns. The sample was discharged immediatelyif there were signs of severe gelling (reported as “gel”). After millingthe sample was discharged into a container. Evaluation for successfulpreparations was based upon examination initially and, if acceptableinitially, after one week at 54° C. storage. Testing included:

1) Appearance—Samples were evaluated as free flowing liquid (reported as“ok”) or gelling (reported as “gel”).

2) Viscosity—The sample was cooled to room temperature. The sample wasstirred with a metal spatula for 40 seconds. Viscosity was measuredusing Brookfield Viscometer LVT, number 3 spindle, and speed settingknob at 60/3. The average of two readings was reported.

3) Storage stability—After one week of storage at 54° C., the sample wasremoved from the oven and allowed to cool to room temperature. Thesample was examined for gelling and separation. If sample separated, theratio of the top layer to the bottom layer was recorded as percentageseparation. A metal spatula was inserted into material and the bottom ofthe container was probed. The spatula was examined for adhered stickysediment, and recorded if found. The viscosity of samples that were notbadly gelled or separated was measured as above and recorded.

Properties examined:

Initially:

appearance—mixture either liquid or gel; desire no gelling

viscosity—desire less than 2000 cps,

preferably less than 1000 cps

After storage for 2 weeks at 54° C.:

appearance—mixture either liquid or gel; desire no gelling

viscosity—desire less than 2000 cps,

preferably less than 1000 cps

% separation—top clear liquid separation; desire less than 10%.

sedimentation—sticky sediment on the bottom of jar; desire none.

Results were classified by the following key words, which are listed inorder of decreasing performance:

ok=Liquid, <1000 cps viscosity, <10% sep, no sediment

sep=Separation greater than 10% after storage.

visc1=Viscosity above 1000 cps before storage.

visc2=Viscosity above 1000 cps after storage.

sed=Sedimentation severe enough to affect viscosity. movement to pass)

bead=gels during or after bead milling (sample must have fluid movementto pass)

gel=Immediately or after homogenization (sample must have fluid pass)

Oil suspensions that exhibit gelling in the homogenizer or bead mill arenot acceptable. All others are acceptable, but in varying degrees ofquality.

TABLE 3 Testing of Polymer Dispersions Active Polymer Homo- Appear-Appear- Sample ID Ingredient No. genizer Bead Mill ance Viscosity anceVisc. % Sep Sed Comp Dithane none gel n/a n/a n/a n/a n/a n/a n/a Da M45-T D-1 Dithane 4 ok ok ok 330 ok 220 3 none M 45-T D-2 Dithane 18 okok ok 270 ok 300 2 none M 45-T Comp Dithane 12 ok gel gel n/a n/a n/an/a n/a Db M 45-T Comp Dithane 15 gel n/a n/a n/a n/a n/a n/a n/a Dc M45-T D-3 Dithane 32 ok ok ok 380 ok 350 1 none M 45-T D-4 Dithane 9 okok ok 320 sep n/a 5 yes M 45-T D-5 Dithane 31 ok ok ok 240 ok 320 2 noneM 45-T D-6 Dithane 36 ok ok ok 310 ok 450 2 none M 45-T D-7 Dithane 37ok ok ok 350 ok 300 2 none M 45-T D-8 Dithane 29 ok ok ok 810 ok 730 1none M 45-T D-9 Dithane 28 ok ok ok 790 ok 1300 1 none M 45-T D-10Dithane 44 ok ok ok 130 ok n/a 0 yes M 45-T Comp Dd Dithane 45 ok ok ok690 gel n/a 2 no M 45-T Comp De Dithane 46 ok ok ok 540 ok 1880 2 no M45-T D-13 Dithane 47 ok ok ok 510 ok 860 5 no M 45-T D-14 Dithane 48 okok ok 410 ok 630 2 slight M 45-T D-15 Dithane 49 ok ok ok 300 ok 240 2slight M 45-T D-16 Dithane 38 ok ok ok 230 ok 230 3 none M 45-T D-17Dithane 21 ok ok ok 620 ok 845 2 none M 45-T D-18 Dithane 20 ok ok ok370 ok 190 2 none M 45-T D-19 Dithane 23 ok ok ok 260 ok 250 2 none M45-T D-20 Dithane 41 ok ok ok 590 ok 440 1 none M 45-T D-21 Dithane 43ok gel gel n/a n/a n/a n/a n/a M 45-T Comp Gallery75df none gel n/a geln/a n/a n/a n/a n/a Ga Comp Gallery75df 18 ok n/a ok 780 gel n/a 0 noneGb G-1 Gallery75df 36 ok n/a ok 430 gel n/a 50 yes G-2 Gallery75df 28 okn/a ok 540 ok 720 2 none G-3 Gallery75df 25 ok n/a ok 390 ok 1250 1 noneComp Imidan70wp none gel n/a gel n/a n/a n/a n/a n/a 1a Comp Imidan70wp18 gel n/a gel n/a n/a n/a n/a n/a 1b Comp Imidan70wp 12 gel n/a gel n/an/a n/a n/a n/a 1c I-1 Imidan70wp 15 ok n/a ok 1200 gel n/a 1 none I-2Imidan70wp 36 ok n/a ok 300 sep n/a 25 yes I-3 Imidan70wp 28 ok n/a ok500 sep 900 5 none I-4 Imidan70wp 25 ok n/a ok 340 sep 470 2 none I-5Imidan70wp 23 ok n/a ok 290 sep 350 5 none I-6 Imidan70wp 43 ok n/a ok500 sep n/a 33 yes Comp Kerb50w none gel n/a n/a n/a n/a n/a n/a n/a KaComp Kerb50w 4 gel n/a gel n/a n/a n/a n/a n/a Kb Comp Kerb50w 18 geln/a gel n/a n/a n/a n/a n/a Kc Comp Kerb50w 12 gel n/a gel n/a n/a n/an/a n/a Kd Comp Ke Kerb50w 15 ok n/a ok 630 sep 650 7 none K-1 Kerb50w36 ok n/a ok 240 sep 320 10 none K-2 Kerb50w 28 ok n/a ok 260 sep 340 7none K-3 Kerb50w 25 ok n/a ok 420 ok 630 0 none K-4 Kerb50w 23 ok n/a ok1040 ok 1600 0 none K-5 Kerb50w 43 ok n/a ok 580 ok 820 0 none CompIndarWP75 none gel n/a n/a n/a n/a n/a n/a n/a IWPa Comp IndarWP75 12gel n/a n/a n/a n/a n/a n/a n/a IWPb Comp IndarWP75 18 gel n/a n/a n/an/a n/a n/a n/a IWPc IWP-1 IndarWP75 23 ok n/a ok 510 gel n/a none noneIWP-2 IndarWP75 31 ok n/a ok 520 ok 900 2 none IWP-3 IndarWP75 36 ok n/aok 450 ok 980 2 none IWP-4 IndarWP75 43 ok n/a ok 690 gel n/a n/a n/aComp Indar none ok gel gel n/a n/a n/a n/a n/a Ia tech Comp Indar 40 okgel gel n/a n/a n/a n/a n/a Ib tech Comp Indar 12 ok gel gel n/a n/a n/an/a n/a Ic tech Comp Indar 15 ok gel gel n/a n/a n/a n/a n/a Id tech I-1Indar 31 ok ok ok 520 ok 670 none none tech I-2 Indar 30 ok ok ok 620 ok620 none none tech I-3 Indar 44 ok ok ok 650 ok 1100 0 none tech CompIndar 45 ok ok ok 780 ok 520 0 none Ie tech Comp If Indar 46 ok ok ok760 ok 620 0 none tech I-4 Indar 47 ok ok ok 600 ok 500 0 none tech I-5Indar 48 ok ok ok 550 ok 380 0 none tech I-6 Indar 49 ok ok ok 480 ok360 0 none tech I-7 Indar 36 ok ok ok 350 ok 515 none none tech I-8Indar 11 ok gel gel n/a n/a n/a n/a n/a tech I-9 Indar 1 ok gel gel n/an/a n/a n/a n/a tech I-10 Indar 2 ok ok ok 1500 gel n/a none none techI-11 Indar 5 ok gel gel n/a n/a n/a n/a n/a tech I-12 Indar 27 ok ok ok650 gel n/a none none tech I-13 indar 29 ok ok ok 680 ok 620 none nonetech I-14 Indar 28 ok ok ok 600 ok 490 none none tech I-15 Indar 39 okok ok 790 gel n/a none none tech I-16 Indar 14 ok ok ok 1520 gel n/anone none tech I-17 Indar 26 ok ok ok 960 gel n/a none none tech I-18Indar 38 ok gel gel n/a n/a n/a n/a n/a tech I-19 Indar 20 ok ok gel n/an/a n/a n/a n/a tech I-20 Indar 24 ok ok ok 1680 gel n/a none none techI-21 Indar 43 ok ok ok 580 ok 800 none none tech Comp Systhane 4 gel n/agel n/a n/a n/a n/a n/a SWPa 40wp Comp Systhane 18 gel n/a n/a n/a n/an/a n/a n/a SWPb 40wp Comp Systhane 12 gel n/a n/a n/a n/a n/a n/a n/aSWPc 40wp SWP-1 Systhane 31 ok n/a ok 470 ok 370 3% none 40wp SWP-2Systhane 1 gel n/a gel n/a n/a n/a n/a n/a 40wp SWP-3 Systhane 36 ok n/aok 530 ok 390 3 none 40wp SWP-4 Systhane 29 ok n/a ok 1010 ok 1700 nonenone 40wp SWP-5 Systhane 44 ok n/a ok 390 ok 380 0 none 40wp CompSysthane 45 ok n/a ok 980 ok 1670 0 none SWPd 40wp Comp Systhane 46 okn/a ok 840 ok 1700 0 none SWPe 40wp SWP-6 Systhane 47 ok n/a ok 550 ok1460 0 none 40wp SWP-7 Systhane 48 ok n/a ok 600 ok n/a n/a n/a 40wpSWP-8 Systhane 49 ok n/a ok 220 sep 300 20 none 40wp SWP-9 Systhane 25ok n/a ok 630 ok 690 0 none 40wp SWP-9 Systhane 23 gel n/a n/a n/a n/an/a n/a n/a 40wp SWP-10 Systhane 7 gel n/a gel n/a n/a n/a n/a n/a 40wpSWP-11 Systhane 43 ok n/a ok 790 ok 790 none none 40wp Comp T-chloro-none ok gel gel n/a n/a n/a n/a n/a TCa thalonil Comp T-chloro- 4 ok gelgel n/a n/a n/a n/a n/a TCb thalonil Comp T-chloro- 18 ok gel gel n/an/a n/a n/a n/a TCc thalonil Comp T-chloro- 12 ok gel gel n/a n/a n/an/a n/a TCd thalonil Comp T-chloro- 15 ok gel gel n/a n/a n/a n/a n/aTCe thalonil TC-1 T-chloro- 31 ok ok ok 160 sep n/a 0 yes thalonil TC-2T-chloro- 36 ok ok ok 160 sep n/a 0 yes thalonil TC-3 T-chloro- 28 ok okok 250 sep n/a 0 yes thalonil TC-4 T-chloro- 25 ok ok ok 240 ok 170 0none thalonil TC-5 T-chloro- 23 ok ok ok 340 ok 180 0 none thalonil TC-6T-chloro- 20 ok gel gel n/a n/a n/a n/a n/a thalonil TC-7 T-chloro- 43ok ok ok 80 gel n/a 0 none thalonil Comp Thifluz- none gel n/a gel n/an/a n/a n/a n/a Ta amide Comp Thifluz- 18 get n/a gel n/a n/a n/a n/an/a Tb amide Comp Thifluz- 4 gel n/a gel n/a n/a n/a n/a n/a Tc amideComp Thifluz- 12 gel n/a gel n/a n/a n/a n/a n/a Td amide Comp Thifluz-15 gel n/a gel n/a n/a n/a n/a n/a Te amide T-1 Thifluz- 36 ok n/a ok560 ok 985 1 none amide T-2 Thifluz- 28 ok n/a ok 820 ok 1530 2 noneamide T-3 Thifluz- 25 ok n/a ok 790 ok 1150 2 none amide T-4 Thifluz- 22gel n/a gel n/a n/a n/a n/a n/a amide T-5 Thifluz- 43 gel n/a gel n/an/a n/a n/a n/a amide Comp Va Visor50w none gel n/a n/a n/a n/a n/a n/an/a Comp Vb Visor50w 4 gel n/a n/a n/a n/a n/a n/a n/a Comp Vc Visor50w18 gel n/a n/a n/a n/a n/a n/a n/a Comp Vd Visor50w 12 gel n/a n/a n/an/a n/a n/a n/a Comp Ve Visor50w 15 gel n/a n/a n/a n/a n/a n/a n/a V-1Visor50w 44 ok n/a ok 400 ok n/a 2 none Comp Vf Visor50w 45 ok n/a ok860 gel n/a 1 none Comp Vg Visor50w 46 ok n/a ok 820 gel n/a 1 none V-2Visor50w 47 ok n/a ok 600 gel n/a 1 none V-3 Visor50w 48 ok n/a ok 580gel n/a 1 n/a V-4 Visor50w 49 ok n/a ok 1400 gel n/a 1 none V-5 Visor50w36 ok n/a ok 580 ok 480 4 none V-6 Visor50w 28 ok n/a ok 570 ok 1100 2none V-7 Visor50w 25 ok n/a ok 380 ok 660 0 none V-8 Visor50w 23 gel n/an/a n/a n/a n/a n/a n/a V-9 Visor50w 43 gel n/a n/a n/a n/a n/a n/a n/a

EXAMPLE 4

Preparation and evaluation of Goal (oxyfluorfen) oil dispersion

10% Polymer No. 50, 42% Goal 95 Technical, 43% 100 neutral oil, and 5%Latron CS-7 (adjuvant-surfactant; from Rohm and Haas Company) werehomogenized together and then Eiger milled for 30 minutes. Asatisfactory dispersion was produced.

EXAMPLE 5

Preparation and evaluation of Goal/Glyphosate oil dispersion

A mixture of 3.35% of Goal (oil flowable), 53.65% Glyphosate, 3.5%Polymer No. 51, 34.5% 100N neutral oil and 5% Triton X-114 were weighedinto a ceramic jar. Quarter inch ceramic milling media was then added tothe ceramic jar. The ceramic jar was placed on a roller and ball milledat 40 rpm for seventy hours. A satisfactory dispersion was produced.

EXAMPLE 6

Preparation and evaluation of RH 7281 dispersion

A mixture of 40% RH7281 benzamide, 3% Polymer No. 52, and 57% 100 Nneutral oil were blended together, homogenized and Eiger milledaccording to the method of Example 3. A sample of the composition wasstored in the laboratory at ambient temperature for seven months andappeared uniform with no separation.

EXAMPLE 7

Preparation and evaluation of glyphosate dispersion

A sample of glyphosate isopropyl ammonium salt was jet air milled to aparticle size of 2-5 microns. A sample of 45.0 g the glyphosateisopropyl ammonium salt, 3.5 g. Polymer No. 53, and 47.85 Chevron 100neutral oil were mixed in a beaker and homogenized in a beaker for 2-3minutes using a Ultra-Turrax T25 homogenizer (made by Janke & Kunke).The product dispersion was acceptable; it was a free-flowing off-whitefluid with no gelling. Viscosity was 303 cps at 25° C. (Brookfieldviscometer, Spindle #1, 100 rpm).

EXAMPLE 8

Preparation and evaluation of Dithane/cymoxanil dispersion

A mixture of 50 parts of Dithane technical grade (86% a.i.), 6 parts ofcymoxanil (95% a.i.), and 5 parts Polymer sample No. 36 made up to 100parts with Orchex 796 oil was prepared. The mixture was homogenized for5 minutes and bead milled for 5 minutes. A uniform dispersion with aviscosity of 2000 cps resulted. After one week at 40° C. the dispersionhad a viscosity of 2500 cps.

EXAMPLE 9

Preparation and evaluation of Dithane/copper hydroxide dispersion

A mixture of 30 parts of Dithane technical grade (86% a.i.), 28 parts ofcopper hydroxide (65% copper) and 5 parts Polymer sample No. 36 made upto 100 parts with Orchex 796 oil was prepared. The mixture washomogenized for 5 minutes and bead milled for 5 minutes. A uniformdispersion with a viscosity of 1500 cps resulted. After one week at 40°C. the dispersion had a viscosity of 1700 cps.

We claim:
 1. A stable dispersion of a pesticide in an agricultural oilcomprising; a pesticide having a particle size from 0.5-10 microns andselected from the group consisting of chlorinated nitrile, triazole,aralkyl triazole, triazole anilide, benzamide, alkyl benzamide, diphenylether, pyridine carboxylic acid, chloroaniline, organophosphate,phosphonic glycine salt, and mixtures thereof; an agricultural oil; andan agricultural oil-soluble polymor, said polymer having a weightaverage molecular weight from 3,000 to 120,000 and comprising 65 to97.5% by weight of an alkyl acrylate, alkyl methacrylato, or mixturethereof, wherein the alkyl group contains an average of at least sevencarbon atoms, and 2.5 to 35% by weight of a copolymerized polar monomer.2. The dispersion of claim 1 wherein said pesticide is selected from thegroup consisting of chlorothalonil, myclobutanil, fenbuconazole,thifluzamide, isoxaben, propyzamide, thiazopyr, oxyfluorfen, glyphosateisopropyl ammonium salt, propanil, phosmet, and mixtures thereof.
 3. Thedispersion of claim 1 wherein said polymer has a weight averagemolecular weight from 20,000 to 75,000.
 4. The dispersion of claim 1wherein said polymer comprises 10-20% by weight of said copolymerizedpolar monomer.
 5. The dispersion of claim 1 wherein said polymer is acopolymer comprising 85-90% by weight C₁₂-C₂₀ methacrylate and 10-20%dimethylaminopropyl methacrylamide.
 6. A stable dispersion of apesticide in an agricultural oil comprising: ethylene bisdithiocarbamatehaving a particle size from 2-10 microns; an agricultural oil; and anagricultural oil-soluble polymer, said polymer having a weight averagemolecular weight from 3,000 to 90,000 and comprising 65 to 100% byweight of an alkyl acrylate, alkyl methacrylate, or mixture thereof,wherein the alkyl group contains an average of at least seven carbonatoms, aud 0 to 35% by weight of a copolymerized polar monomer.
 7. Amethod for forming ti stable dispersion of a pesticide in anagricultural oil comprising admixing a pesticide selected from the groupconsisting of chlorinated nitrile, triazole, aralkyl triazole, triazoleanilide, benzamide. alkyl benzamide, diphenyl ether, pyridine carboxylicacid, chloroaniline, organophosphate, phosphonic glycine salt; anagricultural oil; and an agricultural oil-soluble polymer, said polymerhaving a weight average molecular weight from 3,000 to 120,000 andcomprising 65 to 97.5% by weight of an alkyl acrylate, alkylmethacrylate, or mixture thereof, wherein the alkyl group contains anaverage of at least seven carbon atoms, and 2.5 to 35% by weight of acopolymerized polar monomor and mixing or shearing said admixture untilsaid pesticide has a particle size from 0.5 to 10 microns.
 8. A methodfor forming a stable dispersion of A pesticide in an agricultural oilcomprising admixing ethylene bisdithiocarbamate; an agricultural oil;and an agricultural oil-soluble polymer, said polymer having a weightaverage molecular weight from 8,000 to 90,000 and comprising 65 to 100%by weight of an alkyl acrylate, alkyl methacrylate, or mixture thereof,wherein the alkyl group contains an average of at least seven carbonatoms, and 0 to 35% by weight of a copolymerized polar monomer andmixing or shearing said admixture until said ethylene bisdithiocarbamatehas a particle size from 2 to 10 microns.